JP5866572B1 - Installing the wheel nut set - Google Patents

Abstract

An object of the present invention is to provide a wheel nut that does not become loose even when a large temperature change or load change occurs, and does not exceed the elastic limit. The nut is lightweight and inexpensive, and the installation and removal work is safe and labor-saving. A base nut 20 and a torque nut 40 are provided. The hub side of the base nut 20 has a wheel body pressing portion 6 and a booster fastening convex portion 25 is provided on the opposite surface thereof. The side end of the nut 40 has a box spanner retaining flange having a hexagonal diagonal distance of approximately the diameter, the hub side surface has a boost fastening recess 45, and the opposite surface has a flat surface. On the other hand, after generating the desired axial force PT with the base nut 20 first, the torque nut 40 is tightened, and the base nut 20 is fixed to the hub bolt 2 for operation. [Selection] Figure 1

Description

The present invention relates to a method of attaching a wheel nut that is attached to and detached from an axle when a wheel of an automobile or the like is attached or replaced.

If the wheel nut is loosened, it may hinder the safety of driving the automobile, and it is an important part that requires frequent monitoring of the looseness state during regular inspections. To prevent wheel nuts from loosening, the nuts are tightened to the specified torque by using a torque wrench and the axial force is set to the specified amount. Absent.
(For example, refer to Patent Document 1 and Patent Document 2).
On the other hand, many nut structures have been proposed and put into practical use, but all have tried to stop loosening by obtaining frictional force with the axial force of the bolt. In 1985, things that used the bending force of bolts came out, and the looseness was dramatically improved.
(For example, refer to Patent Document 3 and Non-Patent Document 2).
In 2014, the bending force of bolts was analyzed dynamically, and the structure changed with the development of cold forging by multi-stage former incorporating rapid progress of plastic working, and the quality and production efficiency were epoch-making. It has become something.
(For example, refer to Patent Document 4, Patent Document 5, and Non-Patent Document 1).

  The present invention is an application of the technology completed in Patent Document 4 to a wheel nut set incorporating a dynamic environment unique to an automobile. The dynamic environment refers to a wheel nut that is designed beside a brake device so that it can respond to large temperature changes and can be mass-produced.

  The wheel nut market also has a manual demand in addition to the quantity estimated from the sales volume of new cars. By the way, the annual sales volume of passenger cars in the world in 2014 is 85 million, so that alone, the number of wheel nuts reaches 1.6 billion. There are countless car models, but almost all hub bolts 2 have a nominal diameter d of 12 mm.

Japanese Patent No. 3981827 JP-A-6-10935 Japanese Utility Model Publication No. 50-36123 Japanese Patent No. 4087386 Japanese Patent No. 5540275

"Mechanical Engineering Handbook" A4-109, "The Hertz Official" by the Japan Society of Mechanical Engineers Katsuhiko Wakabayashi, “Development of screws that will never loosen” Journal of the Japan Opportunity Society 2013.12 Vol. 116 No. 1141

  The problem to be solved by the present invention is that the wheel nut attached to the hub hub bolt 2 of the axle does not loosen even in the case of a large temperature change or load change, and frequently does not exceed the elastic limit, so There was a need for a wheel nut structure that would not deform even when attached or removed.

  In addition, the wheel nut is required to be lightweight and inexpensive, and to be safely attached and removed without requiring labor.

The base nut 20 is composed of a base nut 20 and a torque nut 40. The base nut 20 has a regular hexagonal column 21 and has a base female screw 22 at the center axis thereof, and a hub side having a wheel body pressing portion 26. The torque nut 40 has a regular hexagonal column 41 on the outer surface and a box wrench retaining flange 44 on the hub side end, and a torque female screw 42 at the center shaft. In the wheel nut set 10 , the hub side surface has a boost fastening recess 45, and the opposite surface has a plane with an outer peripheral chamfer 46.
First, the base nut 20 is tightened to the hub bolt 2 with half or less of the nut tightening torque specified in the vehicle maintenance manual to generate the axial force PT on the hub bolt 2, and then the torque nut 40 is tightened to tighten the base nut. The main solution can be achieved by adopting a method of attaching a wheel nut set in which 20 and the torque nut 40 are fixed to the hub bolt 2.
Here, the nut tightening torque specified in the maintenance manual of the vehicle refers to the nut tightening torque value specified in the maintenance manual provided for all commercial vehicles, and the numerical value is shown in the range between the upper limit and the lower limit. In the case of the above, the median value is the specified nut tightening torque value. In addition, when there is no vehicle maintenance manual for a small quantity of commercial vehicles, etc., substitute the same value for the hub bolt size and number of equivalent vehicles.

Since the wheel nut of the present invention attached to the hub hub bolt 2 of the axle is made into a nut set by using the base nut 20 and the torque nut 40 which are two parts, the hub bolt 2, the base nut 20 and the torque nut 40 3 The parts could be fixed together.
Conventionally, when tightening to a high specified torque, the axial force PT is close to the yield point, thereby preventing loosening. In the present invention, the axial force PT is stopped at 50% or less of the yield point, and the prevention of loosening is not performed. Securely prevent loosening by fixing the parts together. Details will be described later with reference to the drawings.
Therefore, there is a wheel nut structure that does not loosen even when a large temperature change or load change occurs, and does not "sag" even if it is frequently attached to or removed from the hub hub bolt 2 without exceeding the elastic limit. did it.

The wheel nut set using this structure has become safer and less labor-intensive due to an improved mounting method .

These are Example 1 of the wheel nut set of this invention, and are AA sectional drawings of [FIG. 3]. These are Example 1 of the wheel nut set of this invention, and are BB sectional drawings of [FIG. 3]. These are Example 1 of the wheel nut set of this invention, and are the right view of [FIG. 1]. These are Example 2 of the wheel nut set of this invention, and are FIG. 2 equivalent sectional drawing. These are Example 3 of the wheel nut set of this invention, and are FIG. 2 equivalent sectional drawing. These are Example 4 of the wheel nut set of this invention. These are Example 5 of the wheel nut set of this invention. These are Example 6 of the wheel nut set of this invention. FIG. 4 is a partial cross-sectional view of a box spanner that is widely used as a conventional service tool. FIG. 5 is an exaggerated cross-sectional view showing the anti-loosening action of the wheel nut set of the present invention. These are graphs showing the relationship between the tightening torque and the looseness of the base nut of the present invention. These are the detailed views of the booster fastening part of the wheel nut set of this invention, (a) is a right view of a boosting fastening convex part, (b) is sectional drawing of the torque nut containing a boosting fastening recessed part. Is an exaggerated cross-sectional view showing the catch rate of the base nut of the present invention, where (a) is an intermediate processed product and (b) is a finished product. FIG. 4 is a view showing the principle of preventing wedges from loosening. These are the fragmentary sectional views which added the lock function to the torque nut of this invention. These are sectional drawings of the inexpensive nut nut set embodiment 7 of the present invention.

  Hereinafter, embodiments of the present invention will be described in detail.

The principle of loosening prevention of the wheel nut set according to the present invention will be described with reference to FIG.
[FIG. 10] is a large screw for clarifying the structure, and the play (field term clearance) is clarified.
In FIG. 10, the base nut 20 fastens the wheel body 5 with the axial force PT. In this state, the torque nut 40 is tightened, the concave cylindrical portion 62 hits the inclined cam 60, and the cam surface pressing force PA is generated. When the cam surface pressing force PA is vector-decomposed, it becomes a hub bolt core wire perpendicular force PB and a torque nut biasing force P.
The reaction force of the base nut, which is the same size as the hub bolt core wire right angle force PB, and the direction is opposite, the right angle pressing force PC presses the base nut 20 against the hub bolt 2 with a strong force, so there is no backlash of the base nut 20 and the axial force PT remains unchanged. Retained.

The reaction force of the cam surface pressing force PA becomes a moment M applied to the torque nut 40 on the torque nut / hub bolt in the clockwise direction, and its fulcrum is the hub bolt pressing force PD at the left end of the torque nut and the hub bolt pressing force PE at the right end of the torque nut. It tilts to the right by γ and the backlash disappears. PD and PE are the forces that bend the hub bolt 2, and become the bending stress of the hub bolt 2.
The magnitude of the moment M applied to the torque nut / hub bolt is approximately the product of the torque nut biasing force P and the radius RA of the virtual contact circle.

The torque nut 40 as inclined cam 60 is tightened if tightened gradually rising along the inclined-angle theta, it is Succoth to put around him and thus in close contact with the base nut 20. In order to avoid this, it is preferable to provide an inclination holding stopper 43 having a height of about 1/2 pitch .
In addition, for the tightening force management of the torque nut 40, it is easy to obtain a stable quality by the method of tightening until it comes into contact with the inclined holding stopper 43.

The effect of the present invention will be described with reference to FIG.
Although a conventional wheel nut is uniformly hand-tightened, a tightening torque of 90 to 120 Nm has been specified because it attempts to stop loosening by obtaining a frictional force with the axial force of the bolt. This is about 80% of the elastic limit axial force PU.
When tightening, there is no problem in the elastic region, but when subjected to a large temperature change or load change, the elastic region may pop out and enter the plastic region.
Although the wheel body 5 is often steel, a light alloy such as an aluminum material may be used. Since the hub bolt 2, the base nut 20, and the torque nut 40 are steel, the difference in coefficient of linear expansion becomes stress. The temperature change of the wheel body 5 is about 100 ° C.
In the present invention, since there is confidence in the looseness, the tightening torque is lowered to 40 Nm and the test is performed, but no looseness occurs.
Decreasing the tightening torque causes a great difference in labor, and a woman can perform attachment / detachment work of the wheel body 5.

The principle of preventing wedge loosening will be described with reference to FIG.
It is assumed that the plug 71 is pushed into the wedge 70 having a wedge angle β with a force of f. A surface pressing force q is generated in the wedge 70, and a frictional force u is generated in a direction against f by q. The combined frictional force r 1 is generated from the upper and lower u. The magnitude | size is as [Formula 1-Formula 3].
[Expression 1] f = 2q · sin (β / 2)
[Equation 2] u = μq
[Expression 3] r = 2 μq · cos (β / 2)
Here, if the ratio of the synthetic frictional force r and the force f for pushing into the wedge is the friction drag magnification B,
[Equation 4] B = r / f = μ / tan (β / 2)
B is an amount that indicates difficulty in pulling out, that is, difficulty in loosening.
Incidentally, when the friction coefficient μ = 0.1 and the wedge angle β = 3 ° of the Morse taper (fixed so as to stick), the friction drag magnification B = 3.81. When the wedge angle β = 1.145 ° of the tapered pin that does not loosen, the frictional drag magnification B = 10.01.
On the contrary, the wedge angle β of B = 1 is calculated to be 5.71 °, and when the wedge angle β is larger than that, the wedge angle β is not fixed even if it is pushed in with a strong force f.

δ＝０．４３７３°となる。β＝２・δであるから、Ｂ＝１３．１０である。
傾斜角θ＝１５°であれば、δ＝０．６６４８°、Ｂ＝８．６２である。実験ではこの範囲での好結果を確認した。
古い技術を振り返ると、テーパーピンのテーパ（１：５０）は、長年の試行錯誤から唯一の値になった貴重なデータで、摩擦抗力倍率Ｂ＝１０近傍が緩み止めとして好適であることが推測できる。In the present invention, specifically, the nominal diameter (bolt outer diameter) d = 12 mm and the screw pitches p = 1.25 mm and p = 1.5 mm are implemented, but the latter will be described here.
The composite inclination angle δ is calculated from [Equation 5] from the spiral angle α = 2.48 ° of the effective diameter and the cam inclination angle θ = 10 °.

δ = 0.4373 °. Since β = 2 · δ, B = 13.10.
If the inclination angle θ = 15 °, then δ = 0.6648 ° and B = 8.62. The experiment confirmed good results in this range.
Looking back at the old technology, the taper of the taper pin (1:50) is precious data that has become the only value after many years of trial and error, and it is estimated that the friction drag magnification B = 10 vicinity is suitable as a loosening prevention it can.

Examples will be described below.
[Example 1]
[FIG. 1] is a first embodiment of the wheel nut set according to the present invention, and is a cross-sectional view taken along the line AA of FIG. 3. [FIG. 2] is a first embodiment of the wheel nut set according to the present invention. FIG. 3] is a cross-sectional view taken along the line BB in FIG. 3, and FIG. 3 is a right side view of FIG. 1 in the first embodiment of the wheel nut set of the present invention.
The hub 4 rotates around the axle core 1, and five or four hub bolts 2 are planted on the hub 4 at equiangular intervals at positions separated by the hub bolt core wire 3. The wheel nut set 10 is for attaching / detaching the wheel body 5 to / from the hub 4.
The wheel nut set 10 is composed of a base nut 20 and a torque nut 40. The base nut 20 has a regular hexagonal column 21 on the outer periphery and a base female screw 22 at the center axis thereof, and a wheel body pressing portion 26 on the hub side. Has a booster fastening convex portion 25 on its opposite surface,
The torque nut 40 has a regular hexagonal column 41 on the outer periphery, a box spanner retaining flange 44 having a hexagonal diagonal distance of approximately the diameter at the hub side end, a torque female screw 42 at the center of the center, and a hub side end. The surface has a boost fastening recess 45 and the opposite surface has a flat surface with an outer peripheral chamfer 46;
First, the base nut 20 is fastened to the hub bolt 2 with a predetermined torque to generate a desired axial force PT, and then the torque nut 40 is fastened to fix the base nut 20 and the torque nut 40 to the hub bolt 2 for operation. The structure is such that the torque nut 40 can be loosened and released from fixation.

In FIG. 1 to FIG. 3, there is an axle gap 7 between the wheel body 5 and the hub 4, so that the wheel taper 6 and the nut taper 23 of the base nut 20 are used to rotate the wheel body 5 around the axle core 1. The positioning method is adopted.
The wheel body pressing portion 26 includes a nut taper 23 that monotonously increases from the hub side to the outer periphery, and the taper wedge angle β is 60 °.
In FIG. 2, it is a cross section in which the box spanner stop flange 44 can be seen. The box spanner (passenger car service tool) 35 shown in FIG. 9 has a deep hexagonal hole in the box body 31, and therefore, if the torque nut 40 is not provided with the box spanner retaining flange 44, there is a risk of turning the base nut 20 together. Because there is. Since the lever handle 32 cannot be made too long due to the weight reduction, it has been operated by inserting a pipe material or applying weight, but in the present invention, it is possible to reduce the operating torque.

[Example 2]
[FIG. 4] is a cross-sectional view corresponding to [FIG. 2] in Example 2 of the wheel nut set of the present invention. In this example, the base nut 20 is also provided with a tapered end flange 37. The box spanner (passenger car service tool) 35 does not touch the wheel body 5 and is not damaged.
The nominal diameter d (the outer diameter of the bolt) d of the hub bolt 2 is 12 mm and the standard two-sided width is 19 mm. If the two surface widths are different, the box spanner retaining flange 44 of the torque nut 40 may not be provided.

Example 3
[FIG. 5] is a sectional view corresponding to [FIG. 2] in Example 3 of the wheel nut set of the present invention. A cap 47 was welded to the outside of the torque nut 40 to form a so-called cap nut to protect the hub bolt 2. The cap nut is chrome-plated to give gloss and a large aesthetic factor.
As for the surface treatment of the base nut 20 and the torque nut 40, the base nut 20 may be an inexpensive galvanizing treatment.

Example 4
[FIG. 6] is Example 4 of the wheel nut set of the present invention.
In this system, there is no axle gap 7 and the wheel body 5 is centered by the hub 4. The wheel body pressing portion 26 is a spherical surface 24 having a sphere radius R centered on the hub bolt core wire 3 so as not to form a double center ring.
In FIG. 6, the wheel body 5 is exaggeratedly drawn so that the spherical surface 24 with the spherical radius R is in contact with the 90 ° taper 28 and the spherical gap 8 is conspicuous on the opposite side.

Example 5
[FIG. 7] is Example 5 of the wheel nut set of the present invention.
In this system, the wheel body 5 is a light alloy material such as an aluminum alloy, and, as in the first embodiment, there is an axle gap 7 between the wheel body 5 and the hub 4. Has a positioning knock pin 12 in the center, and a wide flat seat 13 is required.
Moreover, the counter wheel body 5 also carries out the counterbore 9 from flatness request | requirement.

Example 6
[FIG. 8] is Example 6 of the wheel nut set of the present invention.
In this method, the wheel body 5 is a light alloy material such as an aluminum alloy, and, similarly to the fourth embodiment, there is no axle gap 7 between the wheel body 5 and the hub 4, and the wheel body 5 is the hub 4. Center it. The wheel body pressing portion 26 was fitted with a buffer material 27 so as not to form a double center ring, and the opposite wheel body 5 was made into a fool hole 30.
The cushioning material 27 is a soft metal such as an aluminum alloy or a thermosetting resin material, and has a structure in which “sag” is prepared to some extent and is left to periodic inspection and maintenance.

[FIG. 12] is a detailed view of the booster fastening portion of the wheel nut set of the present invention, (a) is a right side view of the booster fastening convex portion, and (b) is an A- of the torque nut including the booster fastening concave portion. It is OB sectional drawing.
(B) The base nut 20 and the torque nut 40 in the figure depict a state in which the hub bolt 2 is removed with the hub bolt core wire 3 as a base line.
A booster fastening recess 45 is provided at the left end of the torque nut 40. In general, the concave portion is formed as a taper relief. However, since the torque nut 40 is provided with a box spanner retaining flange 44 as a necessary condition, the opening 33 has a large spreading strength, so that it can be a cylindrical shape (recess, relief) 34. Cylindrical type will save weight and save materials.

The opening 33 of the torque nut 40 of the present invention has an opening chamfer radius RK, and the opening angle ε must be slightly larger than the cam inclination angle θ. A virtual contact circle 64 indicated by a two-dot chain line is substantially in the vicinity of the opening 33, and the radius RA of the virtual contact circle may be regarded as a radius of a cylindrical shape (recess, relief) 34.
As the torque nut 40 is tightened, the inclination angle γ of the torque nut increases clockwise as described above, and the backlash does not move easily.

The boost fastening convex portion 25 of the base nut 20 has a radius RBB that is substantially perpendicular to the bolt axis and concentric with the radius RA of the virtual contact circle and is smaller than the gap s by more than a semicircle, and the remaining portion is further than the RBB. A small radius RCC is in contact with the virtual contact circle RA and has a rib-like inclined cam 60 continuous with the radius RBB.
In order to maintain the inclination angle γ of the torque nut, an inclination holding stopper 43 having a height of about one half of the pitch p of the screw is provided behind the inclination cam 60.

[FIG. 13] is an exaggerated cross-sectional view showing the catch rate of the base nut of the present invention, (a) is an intermediate processed product, and (b) is a finished product. First, the catch rate is a percentage obtained by dividing the catch height of an entity by the reference catch height.
In response to mass production, the base nut 20 automatically cuts the hoop material, processes it with a cold forging machine (multi-stage former), and plastically processes the base female screw 22 with a vent tap to finish the shape. Thereafter, the surface treatment is performed to complete.
(A) is the final stage of the multistage former, and shows a state where the shaving process is performed. The inner diameter dimension DT before the rolling process at both ends of the female thread is processed in the previous process, and the shaving diameter DST becomes the inner diameter dimension before the rolling process at the center of the female thread, and some punched swarf 52 appears.
(B) The base female screw 22 is plastic-rolled in the vent tap process, and the catching ratio of the finished inner diameter DD at both ends of the female screw is 25 to 45%, and the catching ratio of the finished inner diameter DDD at the center of the female screw is 70. To 85%. The one-third line 51 from the mouths at both ends is a rough standard for three equal parts.
Although the base nut 20 needs to withstand the axial force PT, it has an excessive strength, and the concentricity to the hub bolt core wire 3 is independent of the catching rate, and it is light weight and material saving.
The main object of the present invention is to make it easy to pass through the vent portion of the tap in the vent tap process and to prolong the life of the vent tap.

[FIG. 11] is a graph showing the relationship between the tightening torque and looseness of the base nut of the present invention, and numerically complements the effect of the above-described invention.
In this figure, the horizontal axis represents the tightening torque (Nm), and the vertical axis represents the axial force ratio (%). The axial force ratio is a percentage obtained by dividing the axial force PT by the elastic limit axial force PU. The tightening torque (Nm) is an example in which the nominal diameter (bolt outer diameter) d is 12 mm, 66 is the elastic limit (yield point), and the axial force is the elastic limit axial force PU (kN).
The tightening torque and axial force are directly proportional to the elastic limit (yield point), and the proportionality constant is called the torque coefficient, and strictly speaking, it depends on individual specifications. This range, which is directly proportional, is the elastic range. When the elastic limit (yield point) is exceeded, it becomes a plastic region, so-called “sagging” occurs, and the limit reaches destruction.
The member to be destroyed becomes the weakest hub bolt 2.
Conventional wheel nuts specified a high tightening torque of about 80% of the yield point for the axial force PT, but in the present invention, they were prototyped and tested with less than half of them, and no looseness was observed.
In FIG. 11, the reason why the tail of the conventional / invention mark is long at the top and short at the bottom is that “sagging” occurs due to a temperature change, particularly a high temperature.

FIG. 15 is a partial cross-sectional view in which a lock function is added to the torque nut of the present invention. In order to prevent theft, there is a demand for a device that has a lock function that cannot be removed by an ordinary box spanner and that can be removed only by a key box spanner.
If the outer periphery of the torque nut 40 is a cylinder 48 and the outer diameter is the diagonal distance of the base nut 20, a normal box spanner will not be applied to the base nut 20, and a spline lock 49 is provided on the outer periphery of the torque female screw 42. If you change the width and depth of individual splines, you can create multiple unique ones.

Example 7
[FIG. 15] is a cross-sectional view of the inexpensive wheel nut set of the present invention.
Compared to [Example 1], the prototype of the base nut 20 and the torque nut 40 is replaced with the concave and convex portions, the regular hexagonal column 41 of the torque nut 40 is downsized, and the box spanner retaining flange 44 is eliminated. When tested, it was found that there was no looseness.
In this structure, the base nut 20 that was tightened with the axial force PT was tilted by the taste nut movement of the torque nut 40, but the basics of the loosening prevention were to “squeeze” and satisfy the friction drag magnification ratio B As it has been realized, it was offered as a low-priced wheel nut set.

  As described above, the wheel body 5 is sandwiched with a strong force as in the prior art to prevent loosening by the frictional force. In the embodiment of the present invention, the base nut 20, the torque nut 40, and the hub bolt 2 are components. It proved that it can be surely prevented from loosening even with weak force by fixing, or suggested the possibility of development.

The present invention can be prototyped and tested relatively easily. Moreover, it was possible to do it cheaply because things were small. However, the equipment cost becomes very large when it is mass production for automobiles.
Since the present invention improves safety design, weight reduction, cost reduction, and workability required in the automobile industry, there is a high possibility of being used.

1 Axle core 2 Hub bolt 3 Hub bolt core wire 4 Hub 5 Wheel body 6 Wheel taper 7 Axle clearance 8 Spherical clearance 9 Counterbore 10 Wheel nut set 12 Positioning knock pin 13 Flat seat 20 Base nut 21 Regular hexagonal column 22 Base female screw 23 Nut taper 24 Spherical 25 times Force fastening convex portion 26 Wheel body pressing portion 27 Buffer material 28 90 ° taper 29 Positioning knock hole 30 Baka hole 31 Box body 32 Lever handle 33 Opening portion 34 Cylindrical type (dent, relief)
35 Box Spanner (Passenger Car Service Tool)
37 Tapered end flange 40 Torque nut 41 Regular hexagonal column 42 Torque female screw 43 Inclination holding stopper 44 Box spanner retaining flange 45 Boosting fastening recess 46 Perimeter chamfer 47 Cap 48 Cylinder 49 Spline type lock 51 One third line from the mouth 52 Drain 60 Inclined cam 61 Bolt outer diameter (nominal diameter d)
62 Concave cylindrical part 64 Virtual contact circle 66 Elastic limit (yield point)
70 wedge 71 plug d nominal diameter (bolt outer diameter)
dd Standard dimension of internal diameter of female thread (same as standard dimension of male thread valley diameter)
f Force to push into wedge p Thread pitch q Face pushing force r Synthetic friction force s Gap u Friction force B Friction drag magnification DD Finished inner diameter dimension of both ends of female screw DDD Finished inner diameter dimension of female thread center DST Shaving diameter (rolling process of female thread center) Front inner diameter)
DT Internal diameter before rolling of both ends of female thread M Moment applied to torque nut / hub bolt P Torque nut biasing force PA Cam surface pressing force (Hertz surface pressure basic vector)
PB Hub Bolt Core Wire Right Angle Force PC Base Nut Right Angle Force (Same Size as PB, Reverse Direction)
PD Torque nut left end hub bolt pressing force (same size as PB)
PE Hub bolt pressing force at right end of torque nut (same size as PD and reverse direction)
PT Axial force PU Elastic limit axial force Q Bolt drag R Sphere radius RA Radius of virtual contact circle Radius smaller by clearance s than RBB RA
RCC Radius smaller than radius RBB CK opening chamfer radius α Effective diameter helix angle β Wedge angle γ Torque nut tilt angle δ Composite tilt angle θ Cam tilt angle ε Opening angle μ Friction coefficient

Claims (2)

A method of attaching a wheel to an axle,
The base nut 20 is composed of a base nut 20 and a torque nut 40. The base nut 20 has a regular hexagonal column 21 and has a base female screw 22 at the center axis thereof, and a hub side having a wheel body pressing portion 26. The torque nut 40 has a regular hexagonal column 41 on the outer surface and a box wrench retaining flange 44 on the hub side end, and a torque female screw 42 at the center shaft. In the wheel nut set 10 , the hub side surface has a boost fastening recess 45, and the opposite surface has a plane with an outer peripheral chamfer 46.
First, the base nut 20 is tightened to the hub bolt 2 with half or less of the nut tightening torque specified in the vehicle maintenance manual to generate the axial force PT on the hub bolt 2, and then the torque nut 40 is tightened to tighten the base nut. 20 and a method of attaching a wheel nut set for fixing the torque nut 40 to the hub bolt 2. A method of attaching a wheel to an axle,
The base nut 20 is composed of a base nut 20 and a torque nut 40. The base nut 20 has a regular hexagonal column 21 and has a base female screw 22 at the center axis thereof, and a hub side having a wheel body pressing portion 26. The opposite surface is provided with a boost fastening recess 45 , and the torque nut 40 has a regular hexagonal column 41 on the outer periphery, and the diagonal distance of the regular hexagonal column 41 is smaller than that of the regular hexagonal column 21 on the outer periphery of the base nut 20. and is provided, having a torque female thread 42 in the axis of the center, a surface of the hub side has a booster fastening protrusions 25, the wheel nut set opposite surface thereof which comprises a plane in which the outer peripheral chamfer 46 10
First, the base nut 20 is tightened to the hub bolt 2 with half or less of the nut tightening torque specified in the vehicle maintenance manual to generate the axial force PT on the hub bolt 2, and then the torque nut 40 is tightened to tighten the base nut. 20 and a method of attaching a wheel nut set for fixing the torque nut 40 to the hub bolt 2.

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